Postnatal ocular toxoplasmosis in immunocompetent patients

Abstract

Introduction: Ocular toxoplasmosis is the most common cause of infectious posterior uveitis worldwide. It can be prenatal or postnatal in origin. Despite estimations that postnatal ocular toxoplasmosis is more prevalent, only several cases of proven postnatal ocular toxoplasmosis have been reported in non-epidemic settings. Here, the clinical evolution of ocular toxoplasmosis of conclusively proven postnatal origin in immunocompetent patients is reported.
 Methodology: Postnatal ocular toxoplasmosis was diagnosed based on clinical diagnosis supported by the longitudinal detection of Toxoplasma gondii-specific IgG, IgM and IgA antibodies in the serum as well as by direct detection of the parasite (bioassay) and/or its DNA (real-time PCR) in aqueous humor.
 Results: Three cases involved adults in whom ocular toxoplasmosis developed during primary T. gondii infection, as part of the clinical presentation in two and as the sole manifestation in one patient. The fourth patient was a case of inactive ocular toxoplasmosis in a 14-year-old boy, where postnatal infection was confirmed by exclusion of maternal infection. The causative parasite strain was genotyped in only one case and it belonged to genotype II, the dominant type in Europe. One patient acquired the infection in Africa, suggesting an atypical strain.
 Conclusions: The distinction between prenatal and postnatal ocular toxoplasmosis is only possible in particular clinical situations, and requires extensive laboratory investigation. Genotyping of the parasite strain involved may be important, particularly if atypical strains are suspected, requiring tailored treatment approaches.

Optical Coherence Tomography Angiography Findings in Ocular Toxoplasmosis with Multiple Recurrences

“…The diagnosis of ocular toxoplasmosis relies most heavily on typical clinical findings on the retina; laboratory examination can support a presumptive clinical diagnosis in the case of positive Toxoplasma gondii serology, or rule it out in the case of negative serology. 6 , 14 In these cases, titers of IgM anti- Toxoplasma gondii were negative, however both showed positive IgG anti- Toxoplasma gondii . The positive result of IgG anti- Toxoplasma gondii showed a history of past infection, and the high titers of IgG anti- Toxoplasma gondii may be related to reactivation of infection.…”

Comparison of immunological and molecular methods for laboratory diagnosis of ocular toxoplasmosis in blood, serum and tears in Brazil

“…Overall, OT diagnosis is challenging and mostly depends on typical clinical findings in the retina [13,18]. In addition, laboratory examination can substantiate a presumptive clinical diagnosis in case of positive T. gondii serology or make it possible discarding it in case of negative serology [13,18].…”

“…Overall, OT diagnosis is challenging and mostly depends on typical clinical findings in the retina [13,18]. In addition, laboratory examination can substantiate a presumptive clinical diagnosis in case of positive T. gondii serology or make it possible discarding it in case of negative serology [13,18]. However, some clinical cases do not evidence clear correlation between serum antibody levels and ocular toxoplasmosis symptoms, a fact that highlights the need of further studies aimed at assessing both different laboratory techniques and biological samples to improve the diagnosis of this disease [19].…”